1. Field of the Invention
This invention relates to an image projecting apparatus for use as in a reader printer, which apparatus is adapted to be automatically loaded with a cartridge incorporating therein a microfilm. More particularly this invention relates to an image projecting apparatus which automatically retrieves a desired image from the microfilm in the cartridge and projects the retrieved image on a screen or other image receiving body.
2. Description of the Prior Art
A microfilm reader is used for the purpose of enabling an image recorded on a microfilm to be projected in a magnified size on a screen for easy inspection. A microfilm reader/printer is endowed with an image copying function in addition to the image projecting function. A microfilm scanner projects an image in a microfilm on a solid image pickup element as an image receiving body, reads the projected image therefrom, and stores the image information in an electronic recording medium. Where an image recorded on a microfilm is to be copied on a recording paper without being projected on a screen, an exclusively microfilm grade printer endowed only with an image copying function is used.
The microfilm is now used in a great quantity by enterprises specializing as in commodity distribution and finance because it has been granted admissibility as evidence in legal procedures. It is not uncommon for these large-scale users to keep in storage great many rolls of microfilm on the order of some hundred thousands in quantity. In the case of image retrieval, since a desired image must be sought out of such a collossal volume of microfilm as mentioned above, the microfilm system is required to permit highly efficient retrieval.
A large-scale user keeping in storage such a large volume of microfilm as this makes the practice of carrying out the retrieval of a necessary image as follows.
First, a written instruction designating the cartridge number, frame number, etc. of a particular microfilm roll subjected to retrieval is issued as an output from a computer. Then, in accordance with this written instruction, the designated cartridge is manually taken out of a storage shell holding such an immense volume of microfilm as some hundred thousands of rolls. Usually, a small unit of about ten cartridges is placed in conjunction with the written instruction in a carrier box. This carrier box is transported to an operator tending an image projecting device such as a reader printer. Then, the operator extracts necessary cartridges one by one from the carrier box by consulting the written instruction, manually sets a selected cartridge in place in the image projecting device as a reader printer, and performs retrieval and reproduction of the image of a desired frame number. Thereafter, the cartridge which has undergone the image retrieval is manually removed from the image projecting device, returned to the carrier box, and replaced at the prescribed position in the storage shelf. Finally, the recording papers on which the image has been copied are distributed to pertinent sections of the firm.
In the conventional system, since all of the works of image retrieval except for those of searching and copying are manually carried out, it has been extremely difficult for the operation of searching to be improved any further in efficiency and economy of labor.
For the purpose of solving the problem of the nature described above, the idea of using the device disclosed in Japanese Patent Laid-Open No. 61-130,108, namely such a device as a cartridge changer or a cartridge loader, has been conceived. The device of this kind cannot be employed in its unmodified form for the aforementioned large-scale user. To be specific, if this device is employed for the large-scale user, it inevitably entails numerous demerits such as an unwanted increase in the size and cost of equipment, an addition to the access time for extraction of the desired cartridge, and a consequent marked degradation of the efficiency of retrieval, notwithstanding a merit of economization of labor.